The correct answer is 4, meaning that none of the statements provided in the question are correct.

1. India does have coal-based thermal power plants that use seawater for cooling purposes. For instance, many coastal power plants use seawater.

2. Not all coal-based thermal power plants in India are located in water-abundant districts. In fact, several plants are located in water-stressed districts owing to various reasons such as geographical and logistical convenience.

3. The claim that no coal-based thermal power plant in India is privately owned is also incorrect. Both public (government-owned) and private enterprises operate such power plants in India.

Therefore, all the three statements in the question are incorrect which makes option 4 - `none` the correct answer.